Equazione

Prima le tonde;

[5/4 * (15/15 + 10/15 - 3/15)] - (6/4 + 7/4 - 2/4 - 5/4 + 4/4)^2 + 5 =

= [5/4 * 22/15] - (10/4)^2 + 5 ;

nella parentesi quadra;

si semplifica 5 con 15, rimane 1/3; 22 con 4 resta 11/2; 1 * 11 / (3 * 2);

11/6 - (5/2)^2 + 5 =

= 11/6 - 25/4  + 5 =

mcm = 12

= 22/12 - 75/12 + 60/12 = 

= (22 + 60 - 75) /12 = 7/12.

Ciao @mario8

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Si tratta di un'espressione.

$\small \left[\dfrac{5}{4}·\left(1+\dfrac{2}{3}-\dfrac{1}{5}\right)\right]-\left(\dfrac{3}{2}+\dfrac{7}{4}-\dfrac{1}{2}-\dfrac{5}{4}+1\right)^2+5=$

$\small = \left[\dfrac{5}{4}·\left(\dfrac{15+10-3}{15}\right)\right]-\left(\dfrac{6+7-2-5+4}{4}\right)^2+5=$

$\small = \left[\dfrac{\cancel5^1}{\cancel4_2}·\dfrac{\cancel{22}^{11}}{\cancel{15}_3}\right]-\left(\dfrac{\cancel{10}^5}{\cancel4_2}\right)^2+5=$

$\small = \left[\dfrac{1}{2}·\dfrac{11}{3}\right]-\left(\dfrac{5}{2}\right)^2+5=$

$\small = \dfrac{11}{6}-\dfrac{25}{4}+5=$

$\small = \dfrac{22-75+60}{12}=$

$\small = \dfrac{7}{12}$

5/4·(1 + 2/3 - 1/5) - (3/2 + 7/4 - 1/2 - 5/4 + 1)^2 + 5=

=5/4·(22/15) - (5/2)^2 + 5=

=11/6 - 25/4 + 5=

=7/12

(le somme delle frazioni le lascio fare a te)

[5/4*(1+2/3−1/5)] −(3/2+7/4−1/2−5/4+1)^2 +5 

5/4*(15+10-3)/15-((6+7-2-5+4)/4)^2+5

11/6-25/4+5

(22-75+60)/12

7/12